Technical Field
The invention relates to an apparatus for cutting and aspirating tissue from the human or animal body, in particular for use in vitrectomies, for retinal peeling, etc., having an outer tube, and an inner tube which is arranged concentrically inside the outer tube, with little play, in a manner allowing sliding back and forth, wherein the outer tube is closed on the free end thereof, and has at least one lateral opening, the same with at least one inner cutting edge, close to the free end, wherein the inner tube is open on the free end thereof, and has an outer cutting edge there, and wherein the cutting edges work together by cutting when the inner tube slides with respect to the outer tube.
This is, basically, a surgical cutting instrument for the purpose of removing tissue. It is possible to cut the tissue—on and/or in the body—with the instrument, and aspirate the same from and/or out of the body. Specifically, the instrument can be a very specific cutting instrument which can be used during a vitrectomy to destroy and/or break up the vitreous humor in the eye and remove/aspirate the same from the eye. In addition, it is possible by means of this instrument to remove blood, clotted blood, connective tissue alterations, as well as portions of the retina, during a retinal peeling. A device in this class is fundamentally suitable for use in eye surgery.
Description of Related Art
DE 10 2010 050 337 A1 is hereby named as part of the prior art, by way of example. A device in the class is known from this document, wherein both the outer tube and the inner tube thereof each have two lateral recesses with a dual cutting function. Similar devices are known from U.S. Pat. No. 5,474,532 and U.S. Pat. No. 5,106,364.
It is typical in the devices which define the class that the device must be implemented with extremely little play between the inner wall of the outer tube and the outer wall of the inner tube, such that the cutting edges work together in an ideal manner. The tissue should be cut by the cooperation of the cutting edges, and not, for example, squeezed or sheared. Devices strive to achieve an ideal cooperation of the cutting edges with the least possible play.
The device in question, particularly for use in eye surgery, must comprise the smallest possible dimensions. As such, there are devices in the class wherein the inner tube thereof has a wall thickness of four hundredths of a millimeter. The outer tube has an outer diameter in the range from 0.5 to 0.9 mm, and an inner diameter of 0.35 to 0.37 mm. Accordingly, the outer diameter of the inner tube must be matched to the inner diameter of the outer tube with the least possible play. This makes the construction thereof complicated, and therefore results in considerable manufacturing costs—specifically when the intention is to achieve sufficiently good cutting results.